Ndi self-coupling yellow dye, ink and electrowetting display device

Abstract

The application relates to the field of dye technology, and particularly discloses a NDI self-coupling yellow dye, an ink and an electrowetting display device. 20 The structure formula of the NDI self-coupling yellow dye is as shown in the following formula: wherein R1 is selected from any one of C1-C 20 alkyl, C1-C alkyl with branches; R2 is selected from any one of a phenyl and a substituted alkyl phenyl; and n is a positive integer. The application provides a series of NDI self-coupling yellow dyes with a naphthalimide structure. Through self-coupling, the molar absorption coefficient is increased without changing the color. The prepared NDI self-coupling yellow dye can be dissolved in an organic solvent to prepare an ink suitable for electrowetting display. When the ink is applied to the electrowetting display device, the electrowetting display device has a good aperture ratio and a short switching response time.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of dyes, in particular to an NDI self-coupling yellow dye, ink and electrofluide display device. BACKGROUND

[0002] Electrofluide display technology (EFD) is a display prototype based on electrofluide display principle developed by Philips Company in Holland in 2003. The display principle is to control the surface properties of the hydrophobic layer by changing the voltage, and to change the contact angle of the ink layer on the hydrophobic layer. When no voltage is applied, the ink wets the insulating layer uniformly to form a colored pixel point; when voltage is applied, the electric field changes the surface properties of the hydrophobic layer, so that the interfacial tension between the ink-polar liquid-hydrophobic layer changes, the ink is compressed, and a transparent or substrate color pixel point is formed, thereby obtaining a display image effect.

[0003] The pixel structure of a typical direct drive type electrofluide device is composed of two transparent glass substrates, an ITO conductive layer on the inner side of the upper substrate, and the ITO as a common electrode. On the lower substrate, the conductive ITO layer is etched into a driving electrode. Above the driving electrode is an insulating hydrophobic layer, and the hydrophobicity and dielectric properties of the hydrophobic insulating layer material are crucial, which directly determines the driving voltage of the electrofluide device and the reliability of the device. Above the insulating hydrophobic layer is a pixel grid structure layer, and the pixel grid is filled with non-polar ink liquid, and the polar liquid is filled between the upper substrate and the non-polar ink layer. The upper and lower substrates are assembled together with a glue frame. In order to realize color electrofluide display, the Dutch Liquvista Company proposed two possible structure models: single-layer or multi-layer structure. Single-layer electrofluide color display uses black ink in combination with color filters, but this method reduces the light utilization efficiency and contrast due to the use of filters; while multi-layer electrofluide color display can be formed by superimposing three primary colors (cyan, magenta, yellow), which has higher light utilization efficiency and high contrast. In multi-layer electrofluide color display, yellow molecules mainly use anthraquinone and azo molecules as the main structure, the molar absorption coefficient of anthraquinone yellow dye molecules is low, and the azo yellow dye molecules are mutually soluble in polar liquid.

[0004] Therefore, it is necessary to provide an NDI self-coupling yellow dye, ink and electrofluide display device, which has high solubility and molar absorption coefficient, and is not mutually soluble in polar liquid. SUMMARY

[0005] The present application aims to at least solve one of the technical problems existing in the prior art. To this end, the present application provides an NDI self-coupling yellow dye, an ink and an electrowetting display device. The prepared dye and ink have high solubility and molar absorption coefficient, and are not mutually soluble in polar liquids.

[0006] The first aspect of the present application provides an NDI self-coupling yellow dye.

[0007] Specifically, the structure of the NDI self-coupling yellow dye is as follows:

[0008]

[0009] wherein R1 is selected from any one of C1-C 20 alkyl, C1-C 20 branched alkyl;

[0010] R2 is selected from any one of phenyl, substituted alkyl phenyl;

[0011] n is a positive integer.

[0012] Preferably, R1 is selected from any one of 2-ethyl-1-hexyl, 2-butyl-1-octyl, 2-octyl-1-dodecyl.

[0013] Preferably, R2 is selected from any one of p-t-octyl phenyl, 3,5-di-t-butyl-1-phenyl.

[0014] Preferably, the positive integer is 1, 2 or 3.

[0015] Preferably, the ink comprises

[0016] The second aspect of the present application provides an ink.

[0017] Specifically, the ink comprises a non-polar organic solvent and the NDI self-coupling yellow dye provided in the first aspect.

[0018] Preferably, the ink comprises 5-100 parts by weight of the non-polar organic solvent and 1-30 parts by weight of the NDI self-coupling yellow dye.

[0019] Preferably, the non-polar organic solvent comprises at least one of n-decane, n-dodecane, n-tetradecane, n-hexadecane and fluorine-containing alkane.

[0020] The third aspect of the present application provides a preparation method of the ink.

[0021] Specifically, the preparation method comprises the following steps: dissolving the NDI self-coupling yellow dye in a non-polar organic solvent to prepare the ink.

[0022] The fourth aspect of the present application provides an electrowetting display device.

[0023] Specifically, the electrowetting display device comprises the ink provided by the second aspect.

[0024] Compared with the prior art, the present application has the following beneficial effects:

[0025] The present application provides a series of NDI self-coupling yellow dyes with naphthalimide structure, based on the immiscibility of the main structure of naphthalimide in polar liquid, the solubility is increased by long branched alkyl on the amide, and the absorption peak is red-shifted to yellow by connecting benzene rings on both sides, and the branched alkyl on benzene also helps to increase the solubility. By self-coupling, the molar absorption coefficient is increased without changing the color, and the prepared NDI self-coupling yellow dye can be dissolved in an organic solvent to prepare an ink suitable for electrowetting display, and after the ink is applied to the electrowetting display device, the electrowetting display device has good aperture ratio and short switching response time. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 UV-visible absorption spectrum of ink A of Example 4;

[0027] Figure 2 Molar absorption coefficient result graph of ink A of Example 4;

[0028] Figure 3 UV-visible absorption spectrum of ink B of Example 5;

[0029] Figure 4 Molar absorption coefficient result graph of ink B of Example 5;

[0030] Figure 5 UV-visible absorption spectrum of ink C of Example 6;

[0031] Figure 6 Molar absorption coefficient result graph of ink C of Example 6;

[0032] Figure 7 UV-visible absorption spectrum of ink D of Example 7;

[0033] Figure 8 Molar absorption coefficient result graph of ink D of Example 7;

[0034] Figure 9 Electrowetting display device after power-on of Examples 8-10. DETAILED DESCRIPTION

[0035] In order to make the skilled in the art more clearly understand the technical solutions described in the present application, the following examples are listed for illustration. It should be pointed out that the following examples do not constitute a limitation on the scope of protection required by the present application.

[0036] The raw materials, reagents or devices used in the following examples, unless otherwise specified, can be obtained from conventional commercial channels, or can be obtained by existing known methods.

[0037] Example 1

[0038] An NDI self-coupling yellow dye.

[0039] In a sealed pressure bottle, 0.8000 g (2.9831 mmol) of 1,4,5,8-naphthalene tetraanhydride was dissolved in 20 mL of concentrated sulfuric acid, stirred for 30 min, then 1.8827 g (6.5628 mmol) of 1,3-dibromo-1,3,5-triazine-2,4,6-trione was added, and the reaction was carried out at 130°C for 15 h. Then it was slowly poured into ice water, filtered, washed with water, and dried to obtain 1.4406 g of light yellow solid 1 (quantitative yield).

[0040] The obtained 1.4406 g of light yellow solid 1 was dissolved in 10 mL of N-methyl pyrrolidone (NMP), 1.8641 g (6.2645 mmol) of 2-octyldodecylamine and 10 mL of glacial acetic acid were added, and the reaction was carried out at 90°C for 3 h. Then water was added, extracted with petroleum ether, washed with water, dried, rotary evaporated, and purified by column chromatography (eluent: dichloromethane: petroleum ether = 1:1) to obtain 0.7855 g of orange yellow solid 2, yield: 26.73%.

[0041] The reaction formula of light yellow solid 1 and orange yellow solid 2 is as follows:

[0042]

[0043] 0.4925 g (0.5 mmol) of orange yellow solid 2, 0.3095 g (1.5 mmol) of p-t-octylphenol, and 0.3179 g (2.3 mmol) of potassium carbonate were dissolved in 20 mL of NMP, and the reaction was carried out at 120°C for 3 h under argon protection. Then 1M hydrochloric acid solution was added, filtered, washed with methanol, dried, and purified by column chromatography (eluent: ethyl acetate: petroleum ether = 1:20) to obtain 0.4462 g of orange yellow solid A, which is an NDI self-coupling yellow dye A. Yield: 72.20%.

[0044] The reaction formula of orange yellow solid A is as follows:

[0045]

[0046] The characterization data are as follows:

[0047] 1 H NMR (600 MHz, CDC13): 8.28 (s, 2H), 7.47 (d, J = 8.6 Hz, 4H), 7.09 (d, J = 8.6 Hz, 4H), 4.10 (dd, J = 36.0, 7.3 Hz, 4H), 1.97 (dp, J = 50.5, 6.5 Hz, 2H), 1.77 (s, 4H), 1.42 (s, 12H), 0.86 (dt, J = 9.4, 7.0 Hz, 12H), 0.77 (s, 18H).

[0048] Example 2

[0049] An NDI self-coupling yellow dye.

[0050] Weigh 0.2352 g (0.2388 mmol) of orange-yellow solid 2 prepared in Example 1, 0.0493 g (0.2388 mmol) of p-t-octylphenol, 0.0759 g (0.5492 mmol) of potassium carbonate into 10 mL of tetrahydrofuran, and react at 66°C overnight under argon protection. Add to 1M hydrochloric acid solution, extract with petroleum ether, wash with water, dry, rotary evaporation, and purify by column chromatography (eluent: ethyl acetate: petroleum ether = 1:20) to obtain 0.2171 g of orange-yellow solid 3, yield: 81.9%.

[0051] Weigh 0.1000 g (0.0900 mmol) of orange-yellow solid 3, 0.0274 g (0.1081 mmol) of pinacolatodiboron, 0.0265 g (0.2701 mmol) of potassium acetate, and 0.0132 g (0.0180 mmol) of 1,1-bis(diphenylphosphino)ferrocene palladium dichloride into 4 mL of 1,4-dioxane, vacuum, and replace with argon. React at 90°C for 5 h, quench with water, extract with dichloromethane, wash with water, dry, rotary evaporation, and purify by column chromatography (eluent: ethyl acetate: petroleum ether = 1:20) to obtain 0.0671 g of yellow transparent viscous liquid 4, yield: 64.40%.

[0052] Weigh 0.6444 g (0.5803 mmol) of yellow transparent viscous liquid 4, 0.6717 g (0.5803 mmol) of orange-yellow solid 3, and 0.0671 g (0.0580 mmol) of tetrakis(triphenylphosphine)palladium into 8 mL of 2M potassium carbonate solution and 32 mL of 1,4-dioxane, vacuum, and replace with argon. React at 100°C overnight, add to water, extract with dichloromethane, dry, rotary evaporation, and purify by column chromatography (eluent: ethyl acetate: petroleum ether = 1:20) to obtain 0.9601 g of orange-yellow solid B, which is NDI self-coupling yellow dye B. Yield: 80.27%.

[0053] The reaction formula of orange-yellow solid B is as follows:

[0054]

[0055] Characterization data are as follows:

[0056] 1 H NMR (600 MHz, CDC13): δ 8.48 (s, 2H), 8.33 (s, 2H), 7.50 (d, J = 8.3 Hz, 4H), 7.14 (d, J = 8.5 Hz, 4H), 4.15 (d, J = 7.4 Hz, 4H), 3.83 (d, J = 7.3 Hz, 4H), 1.79 (s, 4H), 1.44 (s, 12H), 0.88 - 0.81 (m, 24H), 0.78 (s, 18H).

[0057] Example 3

[0058] An NDI self-coupling yellow dye.

[0059] A 100 mL round-bottom flask was charged with 0.6247 g (0.5397 mmol) of the yellow transparent viscous liquid 4 prepared in Example 2, 0.2126 g (0.2159 mmol) of 2 prepared in Example 1, 0.0250 g (0.0216 mmol) of tetrakis(triphenylphosphine)palladium, 10 mL of 2M potassium carbonate solution, and 40 mL of 1,4-dioxane, vacuumed, replaced with argon, reacted at 100 °C for 4 h, added to water, extracted with petroleum ether, separated, spin-dried, and purified by column chromatography (eluent: ethyl acetate: petroleum ether = 1:20) to obtain 0.1846 g of orange yellow viscous liquid C, which was NDI self-coupling yellow dye C. Yield: 29.62%.

[0060] Characterization data are as follows:

[0061] 1 H NMR (600 MHz, CDC13): δ 8.53 (s, 2H), 8.48 (s, 2H), 8.35 (s, 2H), 7.51 (d, J = 8.6 Hz, 4H), 7.15 (d, J = 8.4 Hz, 4H), 4.16 (d, J = 7.4 Hz, 4H), 3.90 (dd, J = 13.0, 7.7 Hz, 8H), 1.80 (s, 4H), 1.45 (s, 12H), 0.84 (dddddd, J = 11.5, 9.2, 7.2, 5.6, 1.9 Hz, 36H), 0.79 (s, 18H).

[0062] and obtained 0.3020 g of orange yellow viscous liquid D, which was NDI self-coupling yellow dye D. Yield: 48.46%.

[0063] Characterization data are as follows:

[0064] 1 H NMR (600 MHz, CDC13): δ 8.53 (s, 2H), 8.52 (s, 2H), 8.35 (s, 2H), 7.51 (d, 4H), 7.15 (d, J = 8.5 Hz, 4H), 4.17 (d, J = 7.4 Hz, 4H), 3.89 (dd, J = 27.3, 7.1 Hz, 8H), 1.79 (d, J = 4.9 Hz, 4H), 1.45 (s, 12H), 0.86 - 0.81 (m, 36H), 0.79 (s, 18H).

[0065] The reaction scheme for orange viscous liquid C and orange viscous liquid D is as follows:

[0066]

[0067] Example 4

[0068] An ink.

[0069] The NDI self-coupled yellow dye A synthesized in Example 1 was dissolved in n-decane to prepare ink A.

[0070] Example 5

[0071] An ink.

[0072] The NDI self-coupled yellow dye B synthesized in Example 2 was dissolved in n-decane to prepare ink B.

[0073] Example 6

[0074] An ink.

[0075] The NDI self-coupled yellow dye C synthesized in Example 3 was dissolved in n-decane to prepare ink C.

[0076] Example 7

[0077] An ink.

[0078] The NDI self-coupled yellow dye D synthesized in Example 3 was dissolved in n-decane to prepare ink D.

[0079] Example 8

[0080] An electrowetting display device.

[0081] The ink A prepared in Example 4 was filled into the electrowetting display device.

[0082] Example 9

[0083] An electrowetting display device.

[0084] The ink B prepared in Example 5 is filled into the electrowetting display device.

[0085] Example 10

[0086] An electrowetting display device.

[0087] The ink D prepared in Example 7 is filled into the electrowetting display device.

[0088] Performance test:

[0089] 1. Molar absorption coefficient test:

[0090] The inks of Examples 4-7 are dissolved in petroleum ether, and the optical performance of the inks is tested by a UV-Vis absorption spectrometer. The test results are shown in Table 1.

[0091] Table 1. Test results of ink performance

[0092] Ink name Color Maximum absorption wavelength (nm) Molar absorption coefficient (L-mol -1 ·cm -1 )]]> Ink A Yellow 449 13387 Ink B Yellow 431 23562 Ink C Yellow 431 25134 Ink D Yellow 429 31514

[0093] As shown in Table 1, the molar absorption coefficient increases with the increase of the coupled naphthalimide host, and coupling does not cause color change of the ink.

[0094] 2. Openness test of ink in electrowetting display device:

[0095] The openness of the electrowetting display device refers to the maximum value of the area of the white substrate exposed after the ink in the pixel grid is displaced under the action of the driving voltage, relative to the entire pixel grid area. The openness is an important indicator of the functionality of the reflective display, and can directly reflect the reflectivity of the display device. By testing this performance, the shrinkage characteristics of the ink and the stability of the shrinkage state under the action of the voltage can be evaluated. The electrowetting display devices prepared from Examples 8-10 are selected for the openness test, and the test results are shown in Table 2.

[0096] Table 2. Test results of openness

[0097] Class dv Ratio (%) Example 8 18V 78.04 Example 9 18V 73.62 Example 10 18V 72.52

[0098] 3. Switching response time test of ink in electrowetting display device:

[0099] The response time is a key indicator for measuring the performance of the display. It reflects the response speed of the pixel grid to the electrical driving signal, including the opening time from dark state to bright state and the closing time from bright state to dark state. Shorter response time can reduce the trailing and blur of dynamic picture, and provide smooth and clear visual experience, while too long response time can cause residual image effect, affecting the display quality of high dynamic scenes such as video playing. The electrowetting display devices prepared from Examples 9 and 10 are selected for the switching response time test, and the test results are shown in Table 3.

[0100] Table 3 Response Time Test Results

[0101]

[0102] The preferred embodiments of the present application have been described in detail above. It should be understood by those skilled in the art that modifications and variations to the concepts herein disclosed can be made without departing from the scope of the application, which is defined by the appended claims. Thus, it is intended that the present application cover the modifications and variations of this application provided they come within the scope of the appended claims and their equivalents.

Claims

1. An NDI self-coupling yellow dye, characterized in that The structural formula of the NDI self-coupling yellow dye is as follows: ； Wherein, R1 is selected from C1-C 20 Any one of the alkyl groups; R2 is selected from any one of p-tert-octylphenyl and 3,5-di-tert-butyl-1-phenyl; n is 1, 2 or 3.

2. The NDI self-coupling yellow dye according to claim 1, characterized in that The R1 is selected from any one of 2-ethyl-1-hexyl, 2-butyl-1-octyl, and 2-octyl-1-dodecyl.

3. The NDI self-coupling yellow dye according to claim 1, characterized in that Selected from 、 、 .

4. An ink, characterized in that: The ink comprises a non-polar organic solvent and the NDI self-coupling yellow dye according to any one of claims 1 to 3.

5. The ink according to claim 4, characterized in that The ink comprises 5 to 100 parts of a non-polar organic solvent and 1 to 30 parts of an NDI self-coupling yellow dye in parts by weight.

6. The ink according to claim 4, characterized in that The non-polar organic solvent is selected from at least one of n-decane, n-dodecane, n-tetradecane and n-hexadecane.

7. The method for preparing the ink according to any one of claims 4 to 6, characterized in that: The following steps are involved: The ink is prepared by dissolving NDI self-coupling yellow dye in a non-polar organic solvent.

8. An electrowetting display device, characterized in that: The electrowetting display device comprises the ink according to any one of claims 4 to 6.

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